Seeing 7lbsof boost from a 5lb sts kit
Food for thought...
Bosch style wideband sensors (any WB actually), should be mounted AFTER the turbo. The backpressure created by the turbo will shift the wideband readings, normally richer than actual.
So for all you STS guys, unless you've got the wideband in the back of the car after the turbo your probably leaner than you think
Just a warning
Bosch style wideband sensors (any WB actually), should be mounted AFTER the turbo. The backpressure created by the turbo will shift the wideband readings, normally richer than actual.
So for all you STS guys, unless you've got the wideband in the back of the car after the turbo your probably leaner than you think
Just a warning
12 Second Truck Club
Joined: Feb 2002
Posts: 5,574
Likes: 0
From: Sacramento, CA
I didn't think of that Harlan....
Now on the STS trucks there is only about 12" of pipe coming off the turbo normally. Would'nt this pose a problem for the wideband to read properly? Im my case I have a total of about 3' of pipe before my muffler and can easily take my muffler on and off so would I still be able to weld a bung into the pipe and get a decent reading? Also if you get any kind of oil into the turbine due to leakage or anything how is that going to effect the wideband?
Now on the STS trucks there is only about 12" of pipe coming off the turbo normally. Would'nt this pose a problem for the wideband to read properly? Im my case I have a total of about 3' of pipe before my muffler and can easily take my muffler on and off so would I still be able to weld a bung into the pipe and get a decent reading? Also if you get any kind of oil into the turbine due to leakage or anything how is that going to effect the wideband?
Originally Posted by y2khawk
Food for thought...
Bosch style wideband sensors (any WB actually), should be mounted AFTER the turbo. The backpressure created by the turbo will shift the wideband readings, normally richer than actual.
So for all you STS guys, unless you've got the wideband in the back of the car after the turbo your probably leaner than you think
Just a warning
Bosch style wideband sensors (any WB actually), should be mounted AFTER the turbo. The backpressure created by the turbo will shift the wideband readings, normally richer than actual.
So for all you STS guys, unless you've got the wideband in the back of the car after the turbo your probably leaner than you think
Just a warning
with them close to the pipe end, only idle should be a problem. Once you get enough flow moving through the pipe fresh air reversion shouldn't be a problem.
I've got one in each down pipe, only about 8" from the end. They read pretty well even at idle. Once i'm into the throttle even a little, they read just fine.
a little oil shouldn't hurt them too bad, coolant does more damage. Coating them with oil might give funny readings until them burn off the oil. But I don't think it'll kill them.
I've got one in each down pipe, only about 8" from the end. They read pretty well even at idle. Once i'm into the throttle even a little, they read just fine.
a little oil shouldn't hurt them too bad, coolant does more damage. Coating them with oil might give funny readings until them burn off the oil. But I don't think it'll kill them.
Originally Posted by y2khawk
Food for thought...
Bosch style wideband sensors (any WB actually), should be mounted AFTER the turbo. The backpressure created by the turbo will shift the wideband readings, normally richer than actual.
Bosch style wideband sensors (any WB actually), should be mounted AFTER the turbo. The backpressure created by the turbo will shift the wideband readings, normally richer than actual.
near the bottom of the page
http://wbo2.com/lsu/
MECHAM, no not a good spot. If you can move it into the downpipe it'll work better. Doesn't seem like that's too far to move based on the pics.
The problem is turbos create alot of backpressure, normally 1.5 to 2 times manifold pressure. O2 sensors rely on a fresh air reference on one side of the sensing element, usually provided where the wires go into the sensor. That reference is at normal atmosphereic pressure, and the sensor acts on the sum of pressures for remains O2 in the exhaust stream. Raise the pressure in the exhaust too much and the curve of the sensor is way outta wack.
http://wbo2.com/lsu/
MECHAM, no not a good spot. If you can move it into the downpipe it'll work better. Doesn't seem like that's too far to move based on the pics.
The problem is turbos create alot of backpressure, normally 1.5 to 2 times manifold pressure. O2 sensors rely on a fresh air reference on one side of the sensing element, usually provided where the wires go into the sensor. That reference is at normal atmosphereic pressure, and the sensor acts on the sum of pressures for remains O2 in the exhaust stream. Raise the pressure in the exhaust too much and the curve of the sensor is way outta wack.
I went to the gm dealer here and they let me borrow the tech 2 they have. My intake temps never got above 145 degrees. that was a 4th gear pull all the way up redline. took everything off and seems fine wastegate wise. thought I could of had a kink in the boost gauge line but we moved it and it still reads high. I dont see 7lbs until the top of each gear. As far as my A/f gauge it still reads .92-.93 mv at WOT Since I am at WOT that should be the right reading right.....? I seems to me that I have enough fuel I just need to watch the IAT's right........
Tial gates sometimes come with a pinched diaphragm, but if it was running 5 and is now running 7, that isn't it. I'd check the vacuum lines (as crazy as it sounds, I used to see 5 psi in first and 7 psi in second) due to a very cheap rubber vacuum line used to t the boost gauge into the mani vac. Eventually that line gave out and when I replaced it, viola, no more strange boost numbers.
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Originally Posted by y2khawk
MECHAM, no not a good spot
how much do u think my A/F is off by having it where it is located in the pic?
and where//how far do i put the wideband in the downpipe past the turbo??? (ideally)
sry to hijack yr thread blu-ss
Last edited by MECHAM; Oct 7, 2004 at 05:06 PM.
Originally Posted by blue-ss-camaro
It creeps up to 7lbs why????? I am not running a boost controller right now. But I have the Sts electronic one that you can run two different lbs of boost on.....
Wolfee
Originally Posted by Blackbird
it's not too small.
try getting the signal from the manifold instead of the turbo.
this has fixed this issue for a few people. Cost ya about $5 in vacum line to try.
try getting the signal from the manifold instead of the turbo.
this has fixed this issue for a few people. Cost ya about $5 in vacum line to try.
TECH Addict
Joined: Nov 2001
Posts: 2,659
Likes: 1
From: Bellevue, Wa
I tap into the brakebooster line for all my vacum/boost signals and have nice big individual lines going to everything. don't just T off a dinky little line.
my kit came with a big 5/8th's, I think it is, plastic T to tap into the brakebooster line. I already had one due to my previous blower kits but the point is you should be able to get signal from there too.
may not fix it but it certainly will not hurt to try.
my kit came with a big 5/8th's, I think it is, plastic T to tap into the brakebooster line. I already had one due to my previous blower kits but the point is you should be able to get signal from there too.
may not fix it but it certainly will not hurt to try.
temperature/humidity can mess with boost a lot, that's why i'm a huge fan of electronic boost controllers, if it's set to 5, it will always run 5. for once electronics actually can do something that good old mechanics cannot. you can get them on ebay for cheap. greddy b is popular, as it's the simplest one, but i dont' like it, it offers no extra gizmos, but the price is already high. might as well drop another 100bux extra and have something that can regulate boost based on speed/gear, etc. that's how you actually maintain traction in lower gears.